The medicinal use of cannabis is evolving rapidly in numerous countries. What started as a patient-driven call for legal access to herbal cannabis has developed into a worldwide industry and an expanding class of therapeutic products.
Cannabis is one of the oldest known medicinal plants. In almost every ancient handbook on plant medicine it is described commonly in the form of a tincture or a tea. In ancient Egyptian mummies clues have been found indicating the use of cannabis as a food or medicine.
Like other plants, cannabis is made up of hundreds of chemical compounds. It also comes in many different types. Some people refer to indica, sativa, or ruderalis types (commonly known as hemp), but all of these belong to the same species: Cannabis sativa L.
Cannabis or weed?
Like many mind-altering substances, cannabis possesses many acronyms. Of these, marijuana and hemp are the most well-known. On the street, cannabis is referred to as weed, pot and ganja.Hemp is a word more associated with the fibre-type cannabis plants. Marijuana is the word most used in America and Spanish speaking parts of the world. Another well-known word is hash or hashish – derived from the Hindu-Kush region. Hash is a product extracted from the cannabis plant, containing the THC rich resin separated from the rest of the plant. Hash generally has a higher THC level compared to herbal cannabis.
Food and fibre
The cannabis plant serves multiple purposes. For centuries the plant was grown for the strong and resilient stem fibres. Originally found in warm, arid climates, its home countries include India, Afghanistan and China. Archaeological evidence indicates it was cultivated in China for food and fibre as long as 10,000 years ago. The plant then spread from Asia to Africa and on to the Middle-East. Eventually it arrived in Europe around 500 BC. In the glory days of global shipping by sail, 17th century ships were waterproofed with hemp fibres, and the ropes and sails were made of the same material. In 1545, cannabis was introduced to the western hemisphere by the Spaniards who imported it to Chile for its use as fibre. In North America, cannabis, in the form of hemp, was grown for industrial use in rope, clothing and paper manufacture. Nowadays, cannabis can be found in places all around the world, except in humid, tropical rain forests. Hemp is still grown for its strong fibres, and is used in the car manufacturing industry.
The medicinal use of cannabis was introduced to Europe only recently by a young Irish doctor called William O’Shaughnessy in around 1840. He served for the British East Indian Company, and while in India he recognised the widespread medicinal use of cannabis. In the following decades cannabis gained a short period of popularity in Europe and the United States. At this time dozens of different medicinal preparations were available with cannabis as the active ingredient. They were recommended for indications as various as menstrual cramps, asthma, cough, insomnia, the support of birthing labour, migraine, throat infection and withdrawal from opium use.
What sets the cannabis plant apart from all others are the unique chemicals it contains, the cannabinoids. Cannabinoids are the chief active ingredients that deliver the therapeutic effects of cannabis. No other plant in the world produces cannabinoids, as far as we know. Up until now more than 100 different cannabinoids have been identified. The most well-known of these is THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol). However, other minor cannabinoids present in herbal cannabis are thought to be involved in subtle modulation or enhancement of medicinal effects. This effect may be the result of their independent biological activity, or through synergy with the major cannabinoids THC and CBD.
THC is the most abundant cannabinoid in ‘psychoactive’ cannabis plant types. This substance possesses mind-altering effects, which most users describe as a very pleasant and relaxing experience. THC is also responsible for many of the medicinal effects of cannabis. This may include, among others, reduction of nausea, vomiting, pain and muscle spasms, and improvement of sleep and appetite.
The plant also contains CBD – the second major cannabinoid in cannabis. It has medicinal effects, but does not induce a psychotropic state (i.e. its use does not result in feelings of intoxication). On the contrary, CBD may reduce some of the unwanted effects caused by higher doses of THC. Specifically, co-administration of CBD with THC has been shown to reduce the occurrence or intensity of typical side effects of THC, including heightened euphoria (feeling high), anxiety, and short term memory loss. Moreover, studies indicate that CBD could be effective in easing the symptoms of various difficult-to-control conditions, such as rheumatoid arthritis, diabetes, post-traumatic stress disorder (PTSD), anxiety disorder, and antibiotic-resistant infections.
These functional components of the cannabis plant are produced in resin glands (glandular trichomes), which are located on the surface of the entire plant. The largest concentration of these glands are found in the flowering heads of the female plant. The functional components are released when cannabis is heated to a temperature of 180°C (356°F).
Terpenes are the aromatic compounds that give cannabis varieties their distinctive smells and taste. To date more than 120 different terpenes have been identified in cannabis. Unlike cannabinoids, all major terpenes present in cannabis (e.g. myrcene, alpha-pinene, and beta-caryophyllene) can be found abundantly in nature.
These terpenes are suspected to be involved in different interactions with cannabinoids. They may work synergistically with cannabinoids, to modify or enhance their therapeutic effects in specific ways. Although research on the potential interactions between terpenes and cannabinoids is still in its infancy, terpenes have been shown to produce their own pharmacological effects: anti-inflammatory (myrcene), neuroprotective (myrcene) and analgesic (beta-caryophyllene).
Due to the variety of cannabis terpenes, there are many different combinations in which they can be present in a cannabis plant. Each distinct type (variety, strain) of cannabis has its own unique composition of cannabinoids and terpenes.
Single Convention on Narcotic Drugs
The medicinal use of cannabis slowly disappeared in the beginning of the twentieth century. Its place was largely taken over by opium-based drugs such as codeine and morphine. Cannabis gradually disappeared from all western pharmacopoeias.
In the late fifties the World Health Organisation (WHO) claimed that cannabis and its preparations no longer served any useful medical purpose and are therefore essentially obsolete. In 1961, under the United Nations’ Single Convention on Narcotic Drugs, cannabis and its products were defined as dangerous narcotics with a high potential for abuse.
The single convention prohibits production and supply of cannabis except under license for specific purposes, such as medical treatment and research. It also enforces member states to ensure national drug policy is compliant with this international drug treaty. Medicinal cannabis can, therefore, only be made available to patients by establishing a government run national medicinal cannabis programme. Countries like the Netherlands, Germany, Italy, Canada, Australia, and the Czech Republic already have an official cannabis programme that is in full agreement with the Single Convention.
Please note: If you are a prospective patient you are advised to consult a medical professional before using cannabis as a medicine, and to be well-informed about the local laws regarding cannabis use.